1. Field of Invention
The invention relates to an ink-jet printer and, more particularly, to an ink-jet printer having an ink path formed by ink path forming members that are securely, hermetically interconnected. The invention also relates to a method of forming such an ink path.
2. Description of Related Art
Ink-jet printers that incorporate an ink supply system using a tube are known. Such ink-jet printers have a printhead that ejects ink onto a printing medium, a carriage on which the printhead is mounted, an ink tank that is installed external to the carriage to store ink, and a tube through which ink is supplied from the ink tank to the printhead. One end of the tube is connected to the stationary ink tank, while the other end of the tube is connected to the printhead that reciprocates together with the carriage along a printing medium. Typically, the tube is connected to the printhead frictionally by inserting a joint member of the printhead into the tube.
However, a problem arises in the connection between the tube and the joint member when the printhead repeatedly reciprocates. If the tube moves randomly as the printhead reciprocates, the tube may be loosened or detached from the joint member to permit the entry of air into the ink path. Accumulation of air bubbles in the ink path may lead to a clogging of the ink path and an ink ejection failure.
The tube used for the above-described ink supplying system is typically formed of materials with low vapor and gas permeability, such as polyethylene (PE) and polypropylene (PP), to prevent evaporation of moisture contained in the ink and air permeation through the tube. Compared to tubes formed of flexible materials, such as ethylene rubber and butadiene rubber, the tube formed of the above-described materials, which are generally hard, makes poor contact with the joint member thereby permitting entry of air to the ink path through a gap between the tube and the joint member. As a result, the accumulation of air bubbles in the ink path may lead to a clogging of the ink path and an ink ejection failure.
Japanese Patent No. 2563784 is directed to ink path forming members in an ink-jet printer and discloses an air-tight connection between an ink supply tube and a pipe joint of an ink source or an ink receiver. The tube is inserted into an inner recess of the pipe joint, and the interconnected tube and pipe joint are securely locked by a locking member while a sealing member is interposed between the pipe joint and the locking member. Although the disclosed connecting structure provides an air-tight, secure connection between the ink path forming members, it is fairly complex and requires a large number of members.